DHEA and its sulfate metabolite DHEA-S are negative modulators of GABAA receptor complex (GABA-RC). The proposed research will determine whether variations in DHEA concentration are linked to homeostatic reserve for counteracting sedating effects of GABA-agonists, whether DHEA influences metabolism, and whether there are differential effects of DHEA due to age and gender. Blood samples will be obtained for determination of DHEA, DHEA-S and alprazolam concentrations. Saccadic eye movements, psychomotor performance, memory and sedation will be assessed.